enhancement: Add % success rate to the effect section in the spell editor

[Gibier1]

Description

It would be a nice edit to allow % success rate to the effect option in the spell editor. This way the spell wouldn't always stun/make invulnerable....

Intended Use-Case

This would make combat seems more random and not all the same.

Duplicate Check

• This enhancement idea is not a duplicate to the best of my knowledge.